Research Article |
Corresponding author: Ngoc Long Vu ( ngoclongsie@gmail.com ) Corresponding author: Hong Truong Luu ( hongtruongluu@gmail.com ) Academic editor: Bo Li
© 2021 Ngoc Long Vu, Tran Quoc Trung Nguyen, Gioi Tran, Quoc Dat Nguyen, Hong Truong Luu.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Vu NL, Nguyen TQT, Tran G, Nguyen QD, Luu HT (2021) Primulina scutellifolia, a new species of Gesneriaceae from southern Vietnam. PhytoKeys 187: 15-21. https://doi.org/10.3897/phytokeys.187.77856
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Primulina scutellifolia is described as a new species from Khanh Hoa Province, southern Central Vietnam. It is distinct in the genus in having scutellate leaves that make it a highly potential ornamental plant. The new species looks like P. annamensis in general shapes, sizes and colours of habit, inflorescence, flower, and leaf but is distinguishable by adaxially glabrous and abaxially strigose leaves with serrate margins, scutellate leaf blade and appressed downwards tomentose petiole, sparsely glandular hairs on apical 1/2 of the gynoecium and trapeziform one-lipped stigma with slightly emarginated apex.
Gesneriaceae, new species, Primulina, scutellate leaves, Vietnam
Primulina Hance (Gesneriaceae) is known to have more than 220 species, with the center of species diversity in south and southwest China and North Vietnam (
In Vietnam, Primulina was last revised to have 23 species (
In 2013, the last author of this paper collected a Primulina species in an evergreen broadleaf forest in Khanh Hoa Province. It was misidentified as P. annamensis (Pellegr.) Mich.Möller & A.Weber (
Vietnam. Khanh Hoa Province, Khanh Vinh District, Son Thai Commune, 12°11'39"N, 108°43'30"E, at ca. 1485 m elevation, 01 November 2013, Luu Hong Truong KH0945 (holotype SGN!; isotypes SGN!; PHH!; VNMN!).
Primulina scutellifolia differs from other congeners in having scutellate leaves.
Primulina scutellifolia A, B habit C inflorescence D leaf blade E leaf blade, abaxial surface F petiole G flower, longitudinal dissection H corolla, abaxial lip I staminodes J anthers K opened anther L stigma M opened fruit N calyx lobes, abaxial surface O calyx lobes, adaxial surface P fruit, cross section Q seeds.
Herb, perennial, rosulate, acaulescent. Rhizome terete, woody, to 9 cm long, 3 mm in diameter. Leave 3–13, all basal; petioles cylindrical, appressed downwards tomentose, 6–9 cm long, 0,3 cm in diameter; leaf bade scutellate, 3–5.5 cm long, 2–4 cm wide, adaxially glabrous, shining, plain dark green or dark green with yellowish-greenish spots, leathery, abaxially pale green, reticulate-foveate, sparsely strigose; margins serrate; apex obtuse; base slightly sinuate; venation sunken adaxially, prominent and strigose abaxially; lateral veins 4–6 paired. Inflorescences cymose, axillary, 1–3 flowered. Peduncle reddish brown or greenish, 10–12 cm long, 2–3 mm in diameter, sparsely hirsute. Bracts narrowly triangular, ca 2–3 mm long, ca. 0.5 mm wide at base, same color with peduncle. Calyx 5-lobed from base; lobes equal, lanceolate-oblong 8–10 mm long, 1–2 mm wide, abaxially reddish brown to light green and sparsely glandular hairy, adaxially yellowish green, margin entire, apex acute. Corolla infundibuliform, 4–5 cm long, 1–1.2 cm in diameter at mouth, ca. 0.5 cm in diameter at base, white, violet or white at base and gradually turning to violet towards the apex, outside sparsely glandular hairy, inside smooth and with two yellow stripes on lower part of the corolla. Limb distinctly 2-lipped; upper lip 2-lobed, lobes broadly ovate, 3.5–4 mm long × 7–8 mm wide; lower lip 3-lobed, central lobe orbicular, 7–8 mm long × 7–8 mm wide, lateral ones broadly ovate, 7–8 mm long × 8–9 mm wide. Stamens 2; filaments 29–32 mm long, adnate to the corolla tube base for 16–18 mm, free part 13– 14 mm long and slightly curved, apically sparsely glandular hairy; anthers fused by their entire adaxial surfaces, elliptic, ca. 3 mm long, yellowish. Staminodes 3, linear, translucent; apex capitate, yellowish, glabrous, lateral ones 19–21 mm long, adnate to the corolla for 15–16 mm, free part 4–5 mm long, middle one 16–17 mm long, ca. 1 mm long, adnate to the corolla tube base for 16 mm. Disc ca. 1 mm high, slightly 5-lobed. Ovary linear, 3–3.5 cm long, ca. 2 mm in diameter at base, glabrous on basal 1/2, glandular hairy on apical 1/2. Stigma of only lower lip developing, translucent white, trapeziform, finely hairy, with emarginated apex. Capsule linear, slightly falcate, oblique in relation to the pedicel, reddish brown or greenish and turning to light yellowish, sparsely hairy on the apical part, 65–70 mm long, 5–7 mm in diameter, opening along the dorsal side. Seeds long ellipsoid, translucent brownish.
Flowering was found in August to November and fruiting in September to January.
The specific epithet is derived from its special scutellate leaves.
Báo xuân đón lộc.
Primulina scutellifolia is currently only known from the type location. It grows scattered on humid fertile soils in the evergreen broadleaf forest at elevations of 1,450 to 1,950 m. Our surveys throughout forests of Khanh Hoa and Lam Dong Provinces, which have now been ongoing for more than ten years, confirm its distribution is confined to the eastern slopes of the Hon Giao Range. This is a locally endemic plant.
The plant has been recorded in one population at the type location, with Extent of Occurrence <100 km2 that is impacted by continued logging and not effectively protected. Therefore, we suggest the species to be categorized as Critically Endangered (A1a or B1a,b) (
Primulina scutellifolia is unique in the genus by its scutellate leaves. It may be confused with P. annamensis (Figure
Key morphological differences between Primulina annamensis and P. scutellifolia.
Characters | P. annamensis | P. scutellifolia |
---|---|---|
Petiole | densely pilose | appressed downwards tomentose |
Lamina | flat, with obviously cordate base and entire or crenate margins, abaxially and adaxially densely silky | scutellate, with slightly sinuate base and serrate margins, adaxially glabrous, abaxially sparsely strigose |
Gynoecium | densely glandular hairy on apical >2/3 | glandular hairy on apical 1/2 |
Stigma | bi-lipped; lips bifid with round lobes | upper lip absent; lower lip with slightly emarginated truncate apex |
This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 106.03–2020.38.